NIOSH Recommended Guidelines for Personal Respiratory Protection of Workers in Health-Care Facilities Potentially Exposed to Tuberculosis/V. NIOSH Recommendations for Personal Respiratory Protection
V. NIOSH Recommendations for Personal Respiratory Protection
A. Summary of Conclusions and Recommendations—
- The National Institute for Occupational Safety and Health (NIOSH) concludes that any tuberculosis infection in health-care-facility workers[1] due to occupational transmission is unacceptable. Infection of health-care-facility workers with tuberculosis, whether with or without clinical disease, is a material impairment of these workers' health and establishes a finite probability of subsequently developing clinical tuberculosis. Additionally, treatment of tuberculosis-infected workers with isoniazid (INH+) for chemoprophylactic purposes can present these treated workers with another significant risk of material impairment of their health or functional capacity due to isoniazidrelated health effects (e.g., isoniazid-associated hepatitis).
- NIOSH recommends that wherever there exists the potential exposure of workers to droplet nuclei from a tuberculosis transmitter, the first and highest priority is to reduce the probability of exposure through the use of administrative controls (e.g., rapid identification, early treatment, and isolation of potential tuberculosis transmitters; limiting access to acid-fast bacilli (AFB) isolation rooms; other isolation precautions) implemented in conjunction with engineering controls (e.g., negative-pressure ventilation for AFB isolation rooms to contain any hazard to these rooms; booths, hoods, tents, or other devices for containing droplet nuclei at the source—i.e., a person with infectious pulmonary tuberculosis). However, it is unlikely that the exposure of workers to droplet nuclei can be completely controlled at the infectious source even when these techniques are implemented to a high degree of efficiency. Therefore, for a limited range of specific hazardous locations and procedures, when confirmed or potential tuberculosis transmitters are present, use of effective and reliable personal
- respiratory protection is indicated to assure, to the extent possible, the prevention of transmission. This personal respiratory protection is necessary to reduce the risk of health-care-facility workers becoming infected with tuberculosis due to their inhalation of droplet nuclei.
- NIOSH concludes that the use of isoniazid chemoprophylaxis as a substitute for primary prevention of occupational transmission through all administrative, engineering, and personal respiratory protection controls is not consistent with the provisions of the Occupational Safety and Health Act of 1970.
The following personal respiratory protection recommendations are intended specifically for a limited range of specific hazardous locations and procedures in health-care facilities. These locations primarily include rooms or areas where confirmed or potential tuberculosis transmitters are present. These locations also include any clinical and laboratory areas where certain procedures that could produce infectious airborne materials are performed on: (A) confirmed or potential tuberculosis transmitters or (B) tissue or fluids potentially containing tubercle bacilli. Specific examples are given in Table 3 starting on page 40. These NIOSH recommendations represent the Institute's best judgment as to what is necessary to achieve effective and reliable personal respiratory protection against droplet nuclei for workers in settings where this protection is indicated.
- NIOSH recommends that any confirmed or potential tuberculosis transmitters (10,15) in health-care facilities be rapidly identified with an Admissions Screening Plan, as discussed in section V.B starting on page 37, so that employers can determine whether personal respiratory protection may be indicated for health-care-facility workers.
- NIOSH recommends that, when confirmed or potential tuberculosis transmitters are present or potentially present at hazardous locations and procedures indicated as "medium" in Table 3 starting on page 40, NIOSH-certified, powered, halfmask respirators equipped with high-efficiency particulate powered, (HEPA) filters be used in
- conjunction with an effective respiratory protection program (55,57,89) . The powered airflow to the halfmask respirator facepiece must exceed 4 cubic feet per minute and 6 cubic feet per minute is recommended. Two examples of this respirator type are given in Figures 1 and 2 on pages 34 and 35.
- NIOSH recommends that, when confirmed or potential tuberculosis transmitters are present at certain other hazardous locations and procedures indicated as "high" in Table 3 starting on page 40, NIOSH-certified, positive-pressure , air-line, halfmask respirators be used in conjunction with an effective respiratory protection program (55,57,89). An example of this respirator type is given in Figure 3 on page 36.
- NIOSH recommends that for all potential exposures to droplet nuclei containing tubercle bacilli, prudent public health practice dictates the use of respirators and a respiratory protection program which offers the highest efficacy and reliability of protection equal to or exceeding that specified in Table 3 starting on page 40.
- NIOSH recommends that any respirator provided to workers in health- care-facilities for personal respiratory protection be used in conjunction with an effective respiratory protection program (55,57,89) so that respirator wearers might receive the maximum personal protection their respirators are capable of providing.
- ↑ The term health-care-facility-workers refers to all persons working in a health-care setting-including physicians, nurses, aides, and persons not directly involved in patient care (e.g., dietary, housekeeping, maintenance, clerical, and janitorial staff, and volunteers) (1).
[Figure 1 to Figure 3]
Figure 1—Example A of a NIOSH-Certified, Powered, HEPA-Filter, Halfmask Respirator (MSA Powered, Air-Purifying Respirator, NIOSH approval TC-21C-186).
Figure 2—Example B of a NIOSH-Certified, Powered, HEPA-Filter, Halfmask Respirator (MSA OptimAir 6A, NIOSH approval TC-21C-513).
Figure 3—Example C of a NIOSH-Certified, Positive-Pressure, Air-Line, Halfmask Respirator (MSA Pressure Demand Air-Line Respirator, NIOSH approval TC-19C-158).
B. Identifying Confirmed or Potential Tuberculosis Transmitters in a Health-Care Facility—Worker protection against tuberculosis infection is critically dependent upon rapid identification of any potential tuberculosis transmitters in a health-care facility. This high priority identification can be accomplished with an Admission Screening Plan (15). A qualified infection-control committee in each facility should review information about persons admitted to the facility and develop an Admission Screening Plan. The purpose of this Plan is to specify screening criteria for effectively identifying any individual that is a confirmed or potential tuberculosis transmitter. CDC has previously given the following guidance regarding diagnosing tuberculosis and determining the infectiousness of a person with active tuberculosis (10):
A diagnosis of tuberculosis should be considered for any patient with persistent cough or other symptoms compatible with tuberculosis, such as weight loss, anorexia, or fever. Diagnostic measures for identifying tuberculosis should be instituted for such patients. These measures include history, physical examination, tuberculin skin test, chest radiograph, and microscopic examination and culture of sputum or other appropriate specimens (16,97). Other diagnostic methods, such as bronchoscopy or biopsy, may be indicated in some cases (98,99). The probability of tuberculosis is increased by finding a positive reaction to a tuberculin skin test or a history of a positive skin test, a history of previous tuberculosis, membership in a group at high risk for tuberculosis (see section V.B), or a history of exposure to tuberculosis. Active tuberculosis is strongly suggested if the diagnostic evaluation reveals AFB in sputum, a chest radiograph is suggestive of tuberculosis, or the person has symptoms highly suggestive of tuberculosis (e.g., productive cough, night sweats, anorexia, and weight loss). Tuberculosis may occur simultaneously with other pulmonary infections, such as PCP....
The infectiousness of a person with tuberculosis correlates with the number of organisms that are expelled into the air, which, in turn, correlates with the following factors: a) anatomic site of disease, b) presence of cough or other forceful expirational maneuvers, c) presence of AFB in the sputum smear, d) willingness or ability of the patient to cover his or her mouth when coughing, e) presence of cavitation on chest radiograph, f) length of time the patient has been on adequate chemotherapy, g) duration of symptoms, and h) administration of procedures that can enhance coughing (e.g., sputum induction).
The most infectious persons are those with pulmonary or laryngeal tuberculosis. Those with extrapulmonary tuberculosis are usually not infectious, with the following exceptions: a) nonpulmonary disease located in the respiratory tract or oral cavity, or b) extrapulmonary disease that includes an open abscess or lesion in which the concentration of organisms is high, especially if drainage from the abscess or lesion is extensive (100).
Although the data are limited, findings suggest that tuberculosis patients with acquired immunodeficiency syndrome (AIDS), if smear positive, have infectiousness similar to that of tuberculosis patients without AIDS (CDC/New York City Department of Health, unpublished data).
Infectiousness is greatest among patients who have a productive cough, pulmonary cavitation on chest radiograph, and AFB on sputum smear (31). Infection is more likely to result from exposure to a person who has unsuspected pulmonary tuberculosis and who is not receiving antituberculosis therapy or from a person with diagnosed tuberculosis who is not receiving adequate therapy, because of patient noncompliance or the presence of drug-resistant organisms. Administering effective antituberculosis medication has been shown to be strongly associated with a decrease in infectiousness among persons with tuberculosis (25). Effective chemotherapy reduces coughing, the amount of sputum, and the number of organisms in the sputum. However, the length of time a patient must be on effective medication before becoming noninfectious varies (101); some patients are never infectious; whereas those with unrecognized or inadequately treated drug-resistant disease may remain infectious for weeks or months. Thus, decisions about terminating isolation precautions should be made on a case-by-case basis.
In general, persons suspected of having active tuberculosis and persons with confirmed tuberculosis should be considered infectious if cough is present, if cough-inducing procedures are performed, or if sputum smears are known to contain AFB, and if these patients are not on chemotherapy, have just started chemotherapy, or have a poor clinical or bacteriologic response to chemotherapy. A person with tuberculosis who has been on adequate chemotherapy for at least 2-3 weeks and has had a definite clinical and bacteriological response to therapy (reduction in cough, resolution of fever, and progressively decreasing quantity of bacilli on smear) is probably no longer infectious. Most tuberculosis experts agree that noninfectiousness in pulmonary tuberculosis can be established by finding sputum free of bacilli by smear examination on three consecutive days for a patient on effective chemotherapy. Even after isolation precautions have been discontinued, caution should be exercised when a patient with tuberculosis is placed in a room with another patient, especially if the other patient is immunocompromised.
Other guidance has been given by CDC regarding diagnosing tuberculosis and determining the infectiousness of a person with active tuberculosis, for tuberculosis occurring in correctional institutions (33), high-risk populations (76), and long-term-care facilities (34).
C. Selection of Minimal Acceptable Personal Respiratory Protection—Table 3 starting on page 40 summarizes the types of minimal acceptable personal respiratory protection for healthcare-facility workers potentially exposed to tuberculosis. This table also specifies the conditions, locations, and procedures where personal respiratory protection is indicated.
[Table 3]
Table 3—NIOSH Recommendations for Minimal Acceptable Personal Respiratory Protection for Health-Care-Facility Workers Potentially Exposed to Tuberculosis
These recommendations are indicated for workers in areas where confirmed or potential tuberculosis transmitters are present (see note 1). These recommendations are also indicated for any clinical and laboratory areas where effective infectious-source controls are not in use and certain procedures that could produce hazardous airborne material are performed on: (A) confirmed or potential tuberculosis transmitters or (B) tissue or fluids that could contain tubercle bacilli.
WARNING—These respirators help protect against airborne tuberculosis transmission by reducing the inhaled concentrations. Failure to follow all instructions and limitations on the use of these respirators and/or failure to wear them during all times of exposure can reduce respirator effectiveness and may result in tuberculosis infection and possible death.
No respirator is capable of assuring that all droplet nuclei are prevented from entering the wearer's breathing zone. Misuse of these respirators will increase the risk of inhaling airborne tubercle bacilli and may cause tuberculosis infection and possible death. For this reason, proper training in the use of these respirators is essential in order for the wearer to receive protection (56).
Without an effective respiratory-protection program, respirator wearers are not likely to receive the protection that can be afforded by their respirator, even if it is a correct choice for the situation. As a minimum, compliance with OSHA regulation 29 CFR 1910.134 for occupational respirator use is essential whenever respirators are used by employees, whether required or on a voluntary basis.
Table 3 (continued)—NIOSH Recommendations for Minimal Acceptable Personal Respiratory Protection for Health-Care-Facility Workers Potentially Exposed to Tuberculosis
| Potential for Aerosolization of Droplet Nuclei |
Locations and Procedures Where Confirmed or Potential Tuberculosis Transmitters Are Present or Potentially Present (see note 1) |
Minimal Acceptable Personal Respiratory Protection |
| High | Administration of aerosolized pentamidine (and other aerosols) Any cough-inducing procedure Autopsy rooms, aerosol-generating procedures (e.g., irrigating, sawing) Bronchoscopy procedures Endotracheal intubation/suctioning procedures Sputum induction |
POSITIVE PRESSURE,
AIRLINE, HALFMASK RESPIRATORS USED IN CONJUNCTION WITH AN EFFECTIVE RESPIRATORY PROTECTION PROGRAM |
| Medium | AFB isolation rooms Intensive-care units, routine procedures Laboratories (see note 2) Non-cough-inducting procedures Operating rooms |
POWERED,
HEPA-FILTER, HALFMASK RESPIRATORS USED IN CONJUNCTION WITH AN EFFECTIVE RESPIRATORY PROTECTION PROGRAM |
| Indeterminant (see note 3) |
Admitting areas Emergency rooms (including waiting areas) Hallways Transport of patients Waiting areas (inpatient and outpatient) |
POSSIBILITY OF EXPOSURE POWERED, |
NO POSSIBILITY OF EXPOSURE NO RESPIRATOR NEEDED |
Note 1—As identified with an Admission Screening Plan as discussed in section V.B starting on page 37.
Note 2—Respirators are not indicated when effective infectious-source controls are in use such as given in (44).
Note 3—Whether or not there is a risk depends on whether or not there is a possibility of exposure to a person with infectious tuberculosis.
D. Implementing a Personal Respiratory Protection Program—Whenever personal respiratory protection is necessary as an additional isolation precaution for protection of health-carefacility workers potentially exposed to tuberculosis,an effective protection program must be developed, implemented, personal respiratory administered, and periodically reevaluated (55,57,89):
To be effective, any respiratory protection program, must be supervised by a qualified individual who has sufficient knowledge of respiratory protection. When necessary, employers should obtain the required expertise (e.g., professionals such as industrial hygienists, infection control practitioners , or safety specialists who have been specifically trained in personal respiratory protection) to ensure that the personal respiratory protection program is effectively developed, implemented, administered, and periodically reevaluated. The services of a physician are required to conduct the medical surveillance portion of the program.
Information on how to develop and manage a respiratory protection program is available in technical training courses covering the basics of personal respiratory protection, which are offered by organizations such as NIOSH, OSHA, and the American Industrial Hygiene Association. In addition, similar short courses are available from private contractors and universities.
In order to be effective and reliable, any respiratory protection program must contain at least the following eight elements (55,57,89):
1. Standard Operating Procedures: Written standard operating procedures should contain all information needed to maintain an effective respirator program to meet each user's individual requirements. These procedures should be written so as to be useful to those persons responsible for aspects of the respirator program such as, but not limited to: (1) the program administrator, (2) those responsible for fit testing wearers' face seals and training the respirator wearers, (3) respirator-maintenance workers, and (4) the supervisors responsible for overseeing respirator use in the health-care facility to ensure that respirators are worn when indicated.
2. Medical Surveillance: Health-care-facility workers should not be assigned a task requiring use of respirators unless they are physically able to do the work while wearing the respirator. A physician should determine what health and physical conditions are pertinent for the medical surveillance and periodically review the respirator wearer's medical status.
A physician should classify workers according to their ability to use the necessary respirators. A medical history and at least a limited physical examination are recommended. The medical history and physical examination should emphasize the evaluation of the cardiopulmonary system and should elicit any history of previous respirator use. This history can be an important tool to detect problems that might require further evaluation. The physical examination should seek to detect medical conditions that may be essentially asymptomatic. While chest roentgenograms and/or spirometry may be medically indicated in some determinations of fitness, these need not be routinely performed.
3. Training: Selecting the most protective respirator appropriate for a given hazard is important, but equally important is using the selected device properly each time it is necessary for personal respiratory protection. To help ensure proper use, both supervisors and health-care-facility workers should be trained in selection, use, and maintenance of respirators appropriate for personal protection against airborne tuberculosis. The training program should include instructional material and training covering at least the following elements:
- The reasons why personal respiratory protection is required.
- The nature, extent, and specific hazards of tuberculosis transmission in health-care facilities. The references provided in section IV. A starting on page 16 may aid in the preparation of this material that should include:
- – The specific risks, non-medical consequences of acquiring, and medical consequences of acquiring tuberculosis infection (e.g., risk of developing clinical tuberculosis).
- – The efficacy, benefits, and specific risks of chemoprophylaxis with isoniazid indicated for those infected with tuberculosis (e.g., illness due to INH-induced hepatitis and possible death from hepatitis).
- – The specific risks and medical consequences of developing clinically active tuberculosis ( e.g., risk of death due to tuberculosis in treated and untreated infected persons; illness due to active tuberculosis; risks of transmission to coworkers, family members, patients or clients, and the general public).
- – The nature of transmission and the relative risk of transmission (i.e., infectiousness) due to the aerosolization of droplet nuclei from individuals with differing generation rates of infectious tuberculosis particles (i.e., transmitters) at varying locations and undergoing varying procedures in health-care facilities.
- – Some of the inherent practical limitations of personal respiratory protection programs, admission screening plans, employee tuberculosis skin-test surveillance programs, and infection-control programs that increase the hazard to health-care-workers due to airborne transmission of tuberculosis in their workplace.
- – Information about the risk for life-threatening clinical tuberculosis in persons with immunocompromising conditions.
- An explanation of why engineering controls are not being applied or are not adequate, and of what effort is being made to reduce or eliminate the need for personal respiratory protection.
- An explanation of why a particular type of respirator has been selected and provided for a specific location or procedure.
- An explanation of the operation, and the capabilities and limitations, of the respirator provided.
- Instruction in how the respirator wearer should inspect, don, fit check, and correctly wear their provided respirator.
- An opportunity for each wearer to handle the respirator, learn how to don and wear it properly (i.e., achieve a proper face-seal fit on the wearer's face), check important parts (e.g., battery charge , flow rate, filters, air supply), and wear it in a safe atmosphere.
- An explanation of how the respirator is properly maintained and stored.
- Instruction in how to recognize an inadequately functioning respirator and how to recognize and cope with emergency situations.
4. Face-Seal Fit Testing and Fit Checking: The rationale for and the essential roles of fit tests performed by qualified persons and fit checks performed by respirator wearers before every use are detailed in Table 1 on page 20.
5. Respirator Inspection, Cleaning, Maintenance, and Storage: Scrupulous respirator maintenance should be made an integral part of the overall respirator program. Manufacturers' instructions for inspection, cleaning, and maintenance of respirators should be followed to ensure that the respirator continues to function properly. Wearing poorly maintained or malfunctioning respirators may be more dangerous than not wearing a respirator at all because the worker wearing a defective device will falsely assume that protection is being provided. A proper maintenance program ensures that the worker's respirator remains as effective as it was when new. All respiratory-protection maintenance programs should include at least the following:
- inspection for physical damage or defects
- replacing and disposing of used filter elements as necessary
- cleaning and disinfecting (as indicated by hospital infection control procedures)
- repair
- proper storage (i.e., clean, disinfected respirators placed in a sealed container and stored in a dry, noncontaminated environment).
6. Surveillance of the Health-Care Facility and Exposures of Workers in Health-Care-Facilities: Because air sampling methods for airborne concentrations of droplet nuclei are not currently available, exposures of health-care-facility workers cannot be quantified. However, efforts should be made to periodically evaluate the work environment for changes in ventilation, isolation procedures, work practices (such as frequency of entering AFB isolation rooms), and other factors that may affect the probability of exposure to droplet nuclei. These assessments must be conducted in addition to the Admission Screening Plan discussed in section V.B starting on page 37. Information collected from these surveillance activities should be used to determine if the personal respiratory protection program is effective.
7. Respirator Selection: NIOSH recommends that for all exposures to droplet nuclei, the respirator and respiratory protection program selected should offer efficacy and reliability
of protection equal to or exceeding that specified in Table 3 starting on page 40. All such respirators should be NIOSH-certified (79,80). 8. Periodic Evaluation of the Personal Respiratory Protection Program: Periodic evaluation of the entire personal respiratory protection program is essential to ensure that health-care-facility workers are being adequately protected. The program should be completely evaluated at least once annually, and both the written operating procedures and program administration should be modified as necessary based on the results. This evaluation should be conducted by a qualified program administrator who has overall responsibility for all aspects of the program.
Frequent evaluation of respirator use will determine whether the correct respirators are being used and worn properly. Examination of respirators in use and in storage will indicate the adequacy of respirator maintenance. Wearers should be consulted periodically about their acceptance of respirators, including any discomfort, resistance to breathing, fatigue, interference with vision and communication, restriction of movement, and any interference with job performance and the wearer's confidence in the respirator's efficacy and reliability.
The results of periodic inspections of respirator use, consultations with wearers, surveillance of work area conditions, and medical surveillance of wearers should be reviewed, studied, and analyzed to evaluate the effectiveness and reliability of the personal respiratory protection program. Evidence of the failure of personal respiratory protection (e.g., tuberculosis skin-test conversions) should be aggressively addressed to determine whether the indicated respirator was used properly, and what remedial action is needed. The results of the program evaluation should be presented in a written report that lists plans to correct failures with the target dates for their implementation.